The present invention relates to a take-up winder for winding a yarn produced by a melt-spinning machine, specifically to the technology for accurately maintaining a contact pressure of a bobbin holder for winding yarn and a contact pressure roller rotating following the contact with the bobbin holder, at a designated value by a feedback control.
According to such kind of take-up winder, in the process of forming a package by winding the yarn to a bobbin set on a bobbin holder, the bobbin holder rotates at a high speed, and to make the quality of the yarn to be in a favorable condition by a stable winding, a contact pressure of a contact pressure roller and the package, in other words, a control to adjust the contact pressure is necessary. For a contact pressure control device for such purpose, take-up winders publicized in the Japanese Patent Publication (Tokkou-Hei) No. 7-55764 or the Japanese Unexamined Patent Application Publication (Tokkai-Hei) No. 8-26597 are known.
These take-up winders comprised a pressure detecting means such as a strain sensor for detecting load of a bearing section which supports the contact pressure roller in rotatable form, and adopted a control structure to control the contact pressure applied to the package of the contact pressure roller to be at a targeted value by feeding back the detected value of the pressure detecting means.
According to the take-up winders shown in aforementioned publications, the contact pressure is attempted to be maintained at the target value (or target range) accurately by carrying out a desired feedback control. However, it can be predicted that an expected operation cannot be earned with such means. In other words, a bobbin holder inserted with a plurality of bobbin is supported in cantilever to a machine main body so that the exchanging of packages can be carried out easily, and rotated and driven at a high speed under such condition. Therefore, vibration accompanying rotation generates at all times, the change in the load of the contact pressure roller is intense, and a total of one pair of pressure detecting means is required to both ends of the contact pressure roller. Moreover, some processing means is necessary for handling the detected value of both pairs as one data. Therefore, the control accuracy enduring a practical use cannot be realized.
To solve such problems, corresponding the detected values of the pressure detecting means of the left and the right and suppressing a generation of a change can be proposed as a solution. However, to make the rigidity of the bobbin holder of cantilever support structure to endure the change is a difficult task. Thus, there was a room for improvement for realization of a feedback control with high accuracy and enduring to a practical use.
The object of the present invention is to obtain a contact pressure control device capable of carrying out a feedback control enduring to a practical use by inventing a pressure detecting means and the employment structure of the same.
According to the present invention, the take-up winder comprises a bobbin holder which drives and rotates, a contact pressure roller rotatable following contact pressure of a bobbin set on the bobbin holder, a roller supporting means for supporting the contact pressure roller transferable in the direction contacting and separating from the bobbin, and a contact pressure adjusting mechanism capable of adjusting the contact pressure of the contact pressure roller and the bobbin holder. In the contact pressure control device of such take-up winder, a pressure detecting means for detecting the pressure acting on the contact pressure adjusting mechanism is provided, and a means for controlling the contact pressure adjusting mechanism based on the detected value of the pressure detecting means so that the contact pressure is to be maintained at a designated value is also provided.
The pressure detecting means detects the pressure acting on the contact pressure adjusting mechanism (such as a pneumatic cylinder which supports the contact pressure roller elevating or descending). The contact pressure adjusting mechanism is provided to be located to the base side than the bearing unit of the contact pressure roller in the supporting means of the contact pressure roller. Therefore, comparing to the conventional technology, the vibration accompanying the rotation following a contact with the bobbin holder or a package, is to be damped and a stable detected value can be earned.
The contact pressure adjusting mechanism is a fluid pressure cylinder bridged in the vertical direction between a machine main body which supports the bobbin holder rotatable, and the roller supporting means. The pressure detecting means is a load cell provided directly under the fluid pressure cylinder between the fluid air cylinder and the machine main body.
A roller supporting means for supporting the contact pressure roller is constructed to be held by a fluid pressure cylinder provided in the vertical direction, and a load cell is provided directly below the fluid pressure cylinder. Therefore, a relatively large load of both the roller supporting means and the fluid pressure cylinder act upon the load cell. As a result, comparing to the case in which detecting a minute load change, the fluctuation in detection can be grasped accurately.
The roller supporting means supports a transferring frame supporting the contact pressure roller rotatable which is located in the upper part of the bobbin holder, sliding vertically to the machine main body via a pair of slide supporting mechanism. One fluid pressure cylinder is provided between both slide supporting mechanisms.
Only one load cell is sufficient to be provided directly below the fluid pressure cylinder. Therefore, comparing to the case in which more than two load cells are used, the total cost can be suppressed, and a means for processing a plurality of detected values as one control data, as to average the plurality of the detected values, becomes unnecessary.
The roller supporting means supports a rear anchor of the transferring frame which supports the contact pressure roller rotatable, located in the upper part of the bobbin holder, rotatable to the machine main body. The fluid pressure cylinder is provided between the transferring frame and the machine main body.
The fluid pressure cylinder of short stroke is provided in between the middle of the rear anchor of the transferring frame and the contact pressure roller, and the machine main body. According to the principal of leverage, a relatively large load is acted upon the fluid pressure cylinder, and comparing to the case in which detecting a minute load change, the fluctuation in the detection can be grasped accurately.
When the fluid pressure cylinder is worked on a stroke end of either forward or backward, the forward or backward transferring amount of the fluid cylinder is set so that the total weight of the an elevating frame is to act upon the load cell.
The detail will be described in the following, however, in the stroke end state, the total weight of the weight of the entire elevating frame and the weight of the fluid pressure cylinder is to act upon the load cell provided directly below the fluid pressure cylinder. The total weight is a fixed value made clear by measuring beforehand for example. Therefore, by comparing the fixed value and the actual detected value, the zero-point correction of the load cell can be carried out.